Treatment for Malaria

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QUESTION:

How do you treat malaria?

ANSWER:

Malaria can be treated with a number of different types of medication; which one to use depends on the type of malaria you have, as well as whether resistant strains are known to occur in your area. Below I have copied the response I wrote to a similar question on malaria treatment, posted on the 2nd of May, 2011:

In most cases of non-Plasmodium falciparum malaria (the most deadly form of malaria, found throughout the world but most prevalent in sub-Saharan Africa), and even in some places where P. falciparum has not yet developed resistance, treatment with chloroquine is sufficient.

The dosage will depend on body weight (usually approximated by age). Where there is a risk of chloroquine-resistant malaria occurring, treatment of non-complicated cases will usually consist of orally-administered artemisinin-based combination therapy (or ACT) – again, the dosage will depend on age/weight.

For severe malaria, parenteral ingestion of drugs is required. For the treatment of cerebral malaria, caused by P. falciparum, quinine is the traditional drug of choice, though artemisinin has also been shown to be effective. Anti-convulsants and anti-pyretics (to reduce fever) should also be administered.

In cases of infection with P. vivax or P. ovale, the parasite can become dormant in the liver and result in a relapse of the disease if not treated properly. As such, patients with either of these forms of malaria should also be treated with primaquine.

If you have, or suspect you have a health problem, you should visit a physician for a medical diagnosis and treatment.

Started Late on Anti-malaria Medication

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QUESTION:

I’m in a malarious country and I had no idea about anti-malarials until I got here, so I started taking anti-malaria(doxycicline) two weeks late. It has been three weeks since I started taking the medicine. Do you think it would work or should I stop taking it?

ANSWER:

It depends a bit on where you are, and what types of malaria are in your region. Plasmodium falciparum usually takes between 7 and 14 days for symptoms to develop after exposure; P. vivax and P. ovale take between 9 and 14 days. P. malariae, on the other hand, sometimes doesn’t show symptoms until 30 days after infection. However, the most acute and dangerous form of malaria is that caused by P. falciparum; as such, if you haven’t had any symptoms since you started taking anti-malarials three weeks ago, you should be ok, and it certainly would be advisable that you continue with the preventative medicine while you remain in the malarial area.

It’s also worth mentioning that because of the lag between infection and symptoms, in many cases you need to continue taking antimalarials for some period of time after you leave the malaria zone. Of course, if at any point you start to develop symptoms, such as fever or chills, go to a hospital or see a doctor for prompt diagnosis.

Treatment for malaria in Africa

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QUESTION:

What is the treatment for malaria in Africa?

ANSWER:

The appropriate form of treatment for malaria, regardless of where you are, depends on the type of malaria you have. This can be determined through diagnosis; each of the main malaria parasites that ordinarily infect humans (P. falciparum, P. vivax, P. malariae and P. ovale) looks slightly different under the microscope, although you have to be well trained to tell them apart! Rapid diagnostic tests (RDTs) can also sometimes distinguish between malaria species, although many RDTs only test for P. falciparum, he most acute, severe and deadly of the species.

In much of Africa, P. falciparum is the most common and dangerous form of the disease. In some places, it can be treated with chloroquine, though in many places the parasite has developed resistance to this drug, so other treatment is necessary.

The most common drugs given in areas with known chloroquine-resistant strains of P. falciparum are ACTs (artemisinin-based combined therapies). There are some parts of Africa where other forms of malaria, such as P. ovale and P. vivax, can also occur – it is important to know whether a patient is infected with these species as they require an additional form of treatment, the drug primequine, in order to kill dormant liver stages that characterise these species and can lead to a relapse of infection months or even years after the initial exposure.

What is malaria? What Causes Malaria?

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QUESTIONS:

What is malaria?
What causes malaria?

ANSWER:

I have copied below the text from an earlier question, also asking about the causes of malaria and explaining what it is:

Malaria is a disease caused by a parasitic single-celled animal known as Plasmodium. There are different species of Plasmodium, which cause different kinds of malaria. The main types which infect humans are P. falciparum, P. vivax, P. ovale and P. malariae. The parasite is transmitted by certain species of mosquito; the parasite lives in the human blood stream and so goes in to the mosquito when the insect feeds. When the same individual mosquito then feeds on another person, it transmits parasites into a new host.

The symptoms of malaria are caused by the actions that the parasite undertakes while in the human host. For example, part of its reproductive cycle involves invading and then multiplying inside red blood cells. Once several cycles of reproduction have occurred, the new parasites burst out of the red blood cell, destroying it. The cycles are times so that all the new parasites burst out of the red blood cells at the same time; this coordinated destruction of the red blood cells, either every 24, 48 or 72 hours, depending on the malaria species, causes the one day, two day or three day cycles of fevers and chills that characterize malaria infection episodes.


Malaria symptoms

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QUESTION:

When a person is ill he or she will have what symptoms?

ANSWER:

Malaria can have many different symptoms, but the initial signs are similar to a flu-like illness, with high fever, chills, headache and muscle soreness or aches. A characteristic sign of malaria is cyclical fever, with peaks of severity every two or three days. Additionally, some people will experience nausea, coughing, vomiting and/or diarrhea.

Because these symptoms are quite generic of a wide variety of illnesses, if you live in a malaria-endemic region, it is crucial to be tested when you develop such symptoms, rather than assuming it’s just the flu and soldiering on! If you have recently traveled to a malarial area and start to experience these signs of infection, similarly you should inform your doctor of your travel history, as otherwise they might not recognize your symptoms as potentially that of malaria.

If treated rapidly and with the correct medication, malaria is almost always completely treatable; it is only if treatment is delayed that it becomes more serious, with long-lasting and potentially fatal consequences. Similarly, if you take sensible precautions while living or traveling in malarial areas, such as taking prophylaxis (and taking them as per the instructions, for the full required amount of time!), avoiding being bitten by mosquitoes and sleeping under an insecticide-treated bed-net, you vastly reduce your chances of getting infected in the first place.

It’s also worth noting that different species of Plasmodium, the parasite that causes malaria, cause slightly different manifestations of the disease, and also require different forms of treatment. Plasmodium falciparum has a unique way of affecting the red blood cells it infects, which eventually can result in loss of function of internal organs. ‘Cerebral malaria’ is a particularly deadly version of this, whereby the function of the brain is affected. The cycles of fever, mentioned above, are caused by synchronous rupturing of the red blood cells in the body by the malaria parasite; P. falciparum, P. vivax and P. ovale complete this cycle every 48 hours, resulting in fever cycles of roughly two days (though P. falciparum can be unpredictable); P. malariae, on the other hand, has a cycle lasting 72 hours, so three day cycles of fever are expected. Finally, although many types of malaria can be successfully treated with the drug chloroquine, some strains, and notably of P. falciparum, have become resistant to this treatment. In these cases, artemesinin-based treatment is recommended, usually in combination with other therapies (artemesinin-combination therapy, or ACT). P. vivax, in addition, requires an additional drug, called primaquine, which is used to treat lingering liver stages of the parasite, to prevent recurrence of the infection.

Malaria Treatment

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QUESTION:

Is there any treatment for malaria?

ANSWER:

Yes, treatment is available for malaria and most cases can be cured easily if diagnosed accurately and early. There are several different drugs that are used to treat malaria, and different modes of ingestion.

Most cases of malaria can be treated effectively with oral drugs, usually artemisinin-based combination therapies (which contain a drug called artemisinin, long used in Chinese medicine to treat malaria) or chloroquine. The choice between these will depend on the type of malaria you have (hence the need for accurate diagnosis) as well as whether the area you are in is known to have types of malaria that are resistant to chloroquine. In addition, some types of malaria, notably P. vivax and P. ovale, require an additional drug, known as primaquine, to prevent later relapses of malaria from dormant forms of the parasite, that hide in the liver.

Severe malaria may require the administration of drugs directly into the body, usually intravenously. Quinine is often the first-choice drug at this stage, though artemisinin-based compounds have also been shown to be effective. Severe malaria, sometimes manifesting as cerebral malaria, is usually only caused by P. falciparum, the most deadly of the types of malaria found in humans.

How long has malaria existed?

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QUESTION:

How long has malaria been going on?

ANSWER:

The answer to your question depends on the kind of malaria as well as how exactly you define ‘malaria’. The parasites which cause all forms of malaria, in humans as well as other mammals and birds, belong to a group called Plasmodium; scientists believe, based on genetic information, that this genus evolved around 130 million years ago, which is before the dinosaurs went extinct! These ancient ‘malaria’ parasites probably infected lizards; some types of malaria still infect reptiles today.

Plasmodium parasites have since evolved to infect primates, including humans; some scientists argue that this ‘jump’ has probably occurred several times in evolutionary history, whereas other suggest it has only happened once; the debate on this will likely continue for some time!

In terms of when human malaria first evolved, the four main types of malaria that infects humans are P. vivax, P. malariae, P. ovale and P. falciparum; the first three likely either co-evolved with humans or at least first became associated with infecting humans very soon after anatomically modern humans evolved. This dates these types of malaria back to the Middle Stone Age, which started around 300,000 years ago in Africa.

P. falciparum, on the other hand, probably crossed over much more recently, and the most up-to-date genetic evidence suggests that it evolved from a type of malaria which is found in gorillas. Estimates for when this transfer occurred are shaky at best, but it might have only been in the region of 10,000 years ago.

For more reading on the debate regarding the origin and evolutionary histories of Plasmodium as a whole and human forms of malaria more specifically, the following scientific articles may be a good place to start:

Joy, DA; Feng X, Mu J, Furuya T, Chotivanich K, Krettli AU, Ho M, Wang A, White NJ, Suh E, Beerli P & Su XZ, (2003). ‘Early origin and recent expansion of Plasmodium falciparum’, Science 300 (5617): 318–21

Liu, W; Y Li, GH Learn, RS Rudicell, JD Robertson, BF Keele, JN Ndjango, CM Sanz, DB Morgan, S Locatelli, MK Gonder, PJ Kranzusch, PD Walsh, E Delaporte, E Mpoudi-Ngole, AV Georgiev, MN Muller, GM Shaw, M Peeters, PM Sharp, JC Rayner & BH Hahn (2010), ‘Origin of the human malaria parasite Plasmodium falciparum in gorillas’, Nature 467.

Yotoko KSC & Elisei C (2006), ‘Malaria parasites (Apicomplexa, Haematozoea) and their relationships with their hosts: is there an evolutionary cost for the specialization?’, Journal of Zoological Systematics and Evolutionary Research 44 (4): 265–73

How does malaria infect the body?

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QUESTION:

How does malaria infect the body?

ANSWER:

Malaria is transmitted to humans via certain species of mosquito. The parasite that causes malaria, called Plasmodium (there are several species, which cause slightly different forms of the disease), lives in the saliva of the mosquito and is introduced into the human blood when the mosquito bites through the skin. It is interesting to note that only female mosquitoes transmit malaria; male mosquitoes don’t feed on blood, only on nectar and other plant juices, and their mouth parts are too soft to break human skin!

Once the parasite is in the human bloodstream, it undergoes several different life stages. Throughout, it must evade the human immune system, and it has a number of clever ways to do this. One method is by producing a protein which it attaches to its surface; this acts as a “cloak” against the human immune system and hides the parasite. The parasite also uses other proteins to complete its life cycle, for example several are used to enter red blood cells, where part of the reproductive cycle of the parasite is carried out. Finally, after several transformations and cycles of reproduction, the malaria parasites are released again into the bloodstream, where they can be picked up by another female mosquito, and transported to a different human.

For more information about some of the mechanisms for evading the immune system, check out this article from the BBC website, which summarises some recent findings about Plasmodium falciparum, the malaria parasite which causes some of the most debilitating and deadly malaria cases worldwide.

 

 

How did malaria start?

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QUESTION:

When did malaria happen?

ANSWER:

It is believed that Plasmodium, the parasite which causes malaria in a wide variety of animals, first evolved in reptiles. Even today, reptiles are infected by species of Plasmodium that are related to those that infect humans. The parasite probably then evolved to infect birds, and then, more recently, to infect mammals. Many mammals can be infected with malaria-like parasites, but most commonly rodents (like rats and mice) and primates (including humans).

The exact origins of human malaria are less clear, and indeed, there are several different types of malaria, caused by different Plasmodium species, so it would be expected that there were different evolutionary origins for these different types. The most common and deadly form of human malaria, P. falciparum, was long believed to have crossed over about 500,000 years ago from a closely related chimpanzee malaria species called P. reichnowi, and evolved to infect humans.

However, a recent paper in Nature (Liu et al., “Origin of the human malaria parasite Plasmodium falciparum in gorillas,” in volume 467 and pages 420-425) has used molecular evidence, from almost 3000 samples and several genetic regions, has instead suggested that P. falciparum evolved from a type of malaria which is found in western lowland gorillas. However, the paper did not remark on when this cross-over might have occurred. No doubt more studies will be done on this subject in the near future, which will give us a better idea of when the first cases of truly “human” malaria might have occurred!

Reduce Risk of p.falciparum

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QUESTION:

I am laboratories man. My question is the risk of P. falciparum especially for mother and children is very high.  How can we reduce this risk?

ANSWER:

That’s a crucial question for malaria control. Certainly, as you say, the risk of severe malaria is much greater for young children and for pregnant women. As such, these high risk groups should be targeted during prevention campaigns, as well as for diagnosis and treatment.

There are several methods of prevention, which are suitable for all types of malaria, including P. falciparum. Probably the most effective, and also the most simple, is through the proper use of insecticide-treated bednets. These are often handed out at antenatal clinics to pregnant women, but ensuring that the nets are used properly is more difficult. Proper training, and emphasising that children and pregnant women will benefit most from reduced exposure to mosquitoes, is required. For more on the difficulties and challenges of bednet distribution, you can see Hugo Gouvras’ comment on an earlier question in this Q&A forum – see here: http://www.malaria.com/questions/free-malaria-bednet

The other main method for malaria prevention is through the use of prophylactic drugs, although these have to be taken every day, and so the cost is usually prohibitive for residents of malarial areas. In these areas, there have been successful trials of so-called SP IPT, which stands for sulfadoxine-pyrimethamine intermittent protective treatment. In this regime, malaria in pregnant women is prevented by administering intermittent doses of sulfadoxine-pyrimethamine; usually two doses during the pregnancy (one in the second and one in the third trimester), but monthly doses have also been tested. More frequent doses may be better for women who are also HIV positive, some studies have shown.

Intermittent preventative treatment has also been trialled on young children as a way of reducing the severity and frequency of malarial episodes when the child is most vulnerable. I’m not up to date on the most recent studies on this work, so will ask another one of our experts to comment on the efficacy of IPT, both in children and pregnant women.

Thanks for the question!